Honestly I thought about it and I’m not sure what the intention was. It could have been mounted on the other side of the wall (outside the bathroom) just as easily.

I’ll have to dig it up but I have a photo of the old electric meter from the same place. It was buzzing quite loudly, then it melted. It would have been marginal when installed and was connected to only lights and ceiling fans, then they did a reno and added aircon and water heaters.